U.S. patent number 8,089,851 [Application Number 12/439,038] was granted by the patent office on 2012-01-03 for driving apparatus and recording/reproducing apparatus.
This patent grant is currently assigned to Pioneer Corporation. Invention is credited to Kenjiro Fujimoto, Masahiro Ishimori, Takanori Maeda, Shuntaro Mori.
United States Patent |
8,089,851 |
Fujimoto , et al. |
January 3, 2012 |
Driving apparatus and recording/reproducing apparatus
Abstract
A driving apparatus (1) is provided with: a fixed part (11)
having a fixed-part plane (12); and a driven part (13) having a
driven-part plane (14), which faces the fixed-part plane, and
driven in a direction substantially parallel to the fixed-part
plane, a liquid lubricant (30) is between the fixed-portion plane
and the driven-part plane, the driven-part plane faces the
fixed-part plane such that the driven-part plane is substantially
parallel to the fixed-part plane.
Inventors: |
Fujimoto; Kenjiro (Saitama,
JP), Mori; Shuntaro (Saitama, JP),
Ishimori; Masahiro (Saitama, JP), Maeda; Takanori
(Saitama, JP) |
Assignee: |
Pioneer Corporation (Tokyo,
JP)
|
Family
ID: |
39135585 |
Appl.
No.: |
12/439,038 |
Filed: |
September 1, 2006 |
PCT
Filed: |
September 01, 2006 |
PCT No.: |
PCT/JP2006/317364 |
371(c)(1),(2),(4) Date: |
April 16, 2009 |
PCT
Pub. No.: |
WO2008/026293 |
PCT
Pub. Date: |
March 06, 2008 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20090321188 A1 |
Dec 31, 2009 |
|
Current U.S.
Class: |
369/127;
369/140 |
Current CPC
Class: |
G11B
9/1436 (20130101); B82Y 10/00 (20130101); G11B
9/02 (20130101) |
Current International
Class: |
G11B
7/00 (20060101) |
Field of
Search: |
;369/126,127,140 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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32 02 188 |
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Aug 1993 |
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DE |
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2 377 553 |
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Aug 1978 |
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FR |
|
5-52509 |
|
Mar 1993 |
|
JP |
|
7-60581 |
|
Mar 1995 |
|
JP |
|
10-40597 |
|
Feb 1998 |
|
JP |
|
Other References
International Search Report for PCT/JP2006/317364, mailed Dec. 26,
2006. cited by other.
|
Primary Examiner: Giesy; Adam R
Attorney, Agent or Firm: Nixon & Vanderhye P.C.
Claims
The invention claimed is:
1. A driving apparatus comprising: a fixed part having a fixed-part
plane; and a driven part having a driven-part plane, which faces
the fixed-part plane, and driven in a direction substantially
parallel to the fixed-part plane, a liquid lubricant being between
the fixed-portion plane and the driven-part plane, the driven-part
plane facing the fixed-part plane such that the driven-part plane
is substantially parallel to the fixed-part plane, wherein there is
a balance among (i) a surface tension that driven-part plane
receives in a direction of crossing the driven-part plane from the
lubricant, (ii) a repulsion that the driven-part plane receives in
a direction of crossing the driven-part plane from the lubricant,
and (iii) a force that the driven-part plane receives in the
direction of crossing the driven-part plane from an element other
than the lubricant, and wherein each of said fixed part and said
driven part is formed of a same substrate.
2. The driving apparatus according to claim 1, wherein the
driven-part plane forms a depression with respect to a surface of
said driven part in a surrounding of the driven-part plane.
3. The driving apparatus according to claim 1, wherein the
driven-part plane forms a projection with respect to a surface of
said driven part in a surrounding of the driven-part plane.
4. The driving apparatus according to claim 1, wherein the
fixed-part plane forms a depression with respect to a surface of
said fixed part in a surrounding of the fixed-part plane.
5. The driving apparatus according to claim 1, wherein the
fixed-part plane forms a projection with respect to a surface of
said fixed part in a surrounding of the fixed-part plane.
6. The driving apparatus according to claim 1, wherein the
driven-part plane forms a depression with respect to a surface of
said driven part in a surrounding of the driven-part plane, and the
fixed-part plane forms a projection, which corresponds to the
depression, with respect to a surface of said fixed part in a
surrounding of the fixed-part plane.
7. The driving apparatus according to claim 1, wherein the
driven-part plane forms a projection with respect to a surface of
said driven part in a surrounding of the driven-part plane, and the
fixed-part plane forms a depression, which corresponds to the
projection, with respect to a surface of said fixed part in a
surrounding of the fixed-part plane.
8. The driving apparatus according to claim 1, further comprising a
driving mechanism for driving said fixed part in a substantially
orthogonal direction to the fixed-part plane.
9. A recording/reproducing apparatus comprising: a fixed part
having a fixed-part plane; and a driven part having a driven-part
plane, which faces the fixed-part plane, and driven in a direction
substantially parallel to the fixed-part plane, a liquid lubricant
being between the fixed-portion plane and the driven-part plane,
the driven-part plane facing the fixed-part plane such that the
driven-part plane is substantially parallel to the fixed-part
plane, said driven part being equipped with a recording medium,
said fixed part being equipped with one or a plurality of recording
/ reproducing devices, wherein there is a balance among (i) a
surface tension that driven-part plane receives in a direction of
crossing the driven-part plane from the lubricant, (ii) a repulsion
that the driven-part Plane receives in a direction of crossing the
driven-part plane from the lubricant, and (iii) a force that the
driven-part plane receives in the direction of crossing the
driven-part plane from an element other than the lubricant, and
wherein each of said fixed part and said driven part is formed of a
same substrate.
Description
This application is the U.S. national phase of International
Application No. PCT/JP2006/317364, filed 1 Sep. 2006, the entire
contents of which is hereby incorporated by reference.
TECHNICAL FIELD
The present invention relates to, for example, a driving apparatus
for driving a driven object such as a medium, and a
recording/reproducing apparatus for recording and reproducing
information with respect to a recording medium while driving the
recording medium using such a driving apparatus.
BACKGROUND ART
For example, development has advanced on such a probe memory that
records data onto a recording medium or that reproduces the data
recorded on the recording medium, using each of a plurality of
probes, by displacing the recording medium along a recording
surface of the recording medium with respect to the probe array
including the plurality of probes.
As such a probe memory, for example, as disclosed in a patent
document 1, the following probe memory can be listed as one
specific constituent example: a probe memory in which a first
substrate, a second substrate, and a third substrate are connected
through spacers, wherein the first substrate is provided with a
plurality of probe units, the second substrate is provided with a
mover-side electrode and an elastic part which is formed by
removing one portion of the substrate between a central portion
provided with a recording film and a surrounding portion located
around the central portion, and the third substrate is provided
with a stator-side electrode. In this probe memory the central
portion of the second substrate provided with the recording film is
driven (i.e. displaced) by applying a voltage between the
stator-side electrode and the mover-side electrode to thereby use
the elastic part.
Patent document 1: Japanese Patent Application Laid Open NO. Hei
10-40597
DISCLOSURE OF INVENTION
Subject to be Solved by the Invention
However, the aforementioned probe memory does not have a structure
for supporting the recording film, which is a driven part driven by
a force acting in the lamination direction of the substrates (i.e.
a direction orthogonal or perpendicular to the horizontal surface).
The recording film, which is the driven part, is supported by a
force of the elastic part acting in a direction crossing the
lamination direction of the substrates (i.e. a direction parallel
to the horizontal surface); namely, the recording film, which is
the driven part, is constructed as if it floated in the air in the
lamination direction of the substrates. Thus, there is such a
technical problem that the position of the recording film, which is
the driven part, in the lamination direction of the substrates is
possibly changed without intentions. In other words, there is such
a technical problem that even if it is tried to drive the driven
part by a desired amount in the direction parallel to the
horizontal surface, the deflection, distortion, or the like of the
elastic part, which can be caused by the drive, possibly causes the
unintentional change in the position of the driven part in the
perpendicular direction to the horizontal surface. Such a technical
problem leads to lower accuracy in micro devices such as MEMS
(Micro Electro Mechanical Systems) in which the driven part needs
to be driven in units of millimeters, micrometers, or nanometers,
and it is not preferable.
In view or the aforementioned problems, it is therefore an object
of the present invention to provide, for example, a driving
apparatus which can preferably drive a driven part, and a
recording/reproducing apparatus which is provided with such a
driving apparatus.
Means for Solving the Subject
The above object of the present invention can be achieved by a
driving apparatus according to claim 1, provided with: a fixed part
having a fixed-part plane; and a driven part having a driven-part
plane, which faces the fixed-part plane, and driven in a direction
substantially parallel to the fixed-part plane, a liquid lubricant
being between the fixed-portion plane and the driven-part plane,
the driven-part plane facing the fixed-part plane such that the
driven-part plane is substantially parallel to the fixed-part
plane.
The above object of the present invention can be achieved by a
recording/reproducing apparatus according to claim 11, provided
with: a fixed part having a fixed-part plane; and a driven part
having a driven-part plane, which faces the fixed-part plane, and
driven in a direction substantially parallel to the fixed-part
plane, a liquid lubricant being between the fixed-portion plane and
the driven-part plane, the driven-part plane facing the fixed-part
plane such that the driven-part plane is substantially parallel to
the fixed-part plane, the driven part being equipped with a
recording medium, the fixed part being equipped with one or a
plurality of recording/reproducing devices.
The operation and other advantages of the present invention will
become more apparent from the embodiments explained below.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a cross sectional view conceptually showing the structure
of a driving apparatus in a first example.
FIG. 2 is a cross sectional view conceptually showing an aspect
when a driven part provided for the driving apparatus in the first
example is displaced.
FIG. 3 is a cross sectional view conceptually showing the structure
of a driving apparatus in a second example.
FIG. 4 is a top view conceptually showing the structure when the
driving apparatus in the second example is observed in a
z-direction.
FIG. 5 is a cross sectional view conceptually showing the structure
of a driving apparatus in a third example.
FIG. 6 is a cross sectional view conceptually showing the structure
of a driving apparatus in a fourth example.
FIG. 7 is a cross sectional view conceptually showing the structure
of a driving apparatus in a fifth example.
FIG. 8 is a cross sectional view conceptually showing the structure
of a driving apparatus in a sixth example.
FIG. 9 is a cross sectional view conceptually showing the structure
of a driving apparatus in a seventh example.
FIG. 10 is a cross sectional view conceptually showing the
structure of a driving apparatus in an eighth example.
FIG. 11 are cross sectional views conceptually showing the
structure of a driving apparatus in a ninth example.
FIG. 12 is a cross sectional view conceptually showing a first
structure of a recording/reproducing apparatus in an example
FIG. 13 is a cross sectional view conceptually showing a second
structure of the recording/reproducing apparatus in the
example.
FIG. 14 are cross sectional views conceptually showing the
manufacturing process of the driving apparatus in the first
example.
DESCRIPTION OF REFERENCE CODES
1 driving apparatus 11 case 12 fixed-part plane 13 driven part 14
driven-part plane 15 actuator 16 reference part 30 lubricant 41
probe head 42 probe 50 actuator 100, 101 recording/reproducing
apparatus 200 driven object 201 recording medium 300 SOI substrate
301, 303 silicon layer 302 silicon dioxide layer
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, as the best mode for carrying out the invention, an
explanation will be given on embodiments of the driving apparatus
and the recording/reproducing apparatus of the present
invention.
(Embodiment of Driving Apparatus)
An embodiment of the driving apparatus of the present invention is
a driving apparatus provided with: a fixed part having a fixed-part
plane; and a driven part having a driven-part plane, which faces
the fixed-part plane, and driven in a direction substantially
parallel to the fixed-part plane, a liquid lubricant being between
the fixed-portion plane and the driven-part plane, the driven-part
plane facing the fixed-part plane such that the driven-part plane
is substantially parallel to the fixed-part plane.
According to the embodiment of the driving apparatus of the present
invention, it is provided with the fixed part and the driven part
which is driven (i.e. displaced) with respect to the fixed part.
The fixed part has the fixed-part plane, and the driven part has
the driven-part plane. In other words, the fixed part and the
driven part have the respective planes at mutually facing
positions. In other words, the fixed part and the driven part are
constructed such that mutually facing portions are planar.
Incidentally, the "plane" in the embodiment broadly includes a
surface which can be regarded as the plane as a whole even if the
surface has unevenness, a hole, or the like, as well as a literally
pure plane. Moreover, each of the fixed-part plane and the
driven-part plane may have a plurality of planes of different
heights. In short, the shapes of the portions in which the fixed
part faces the driven part only need to be planar in these
portions. Then, the driven part is driven in the direction
substantially parallel to the fixed-part plane, for example, by the
action of an actuator or the like.
In the embodiment, in particular, the liquid lubricant exists at
the space between the fixed part and the driven part; namely, the
fixed-part plane faces the driven-part plane in the direction
substantially parallel to the normal line of the fixed-part plane
(in other words, in a direction of crossing or substantially
perpendicular to a direction that the driven device is driven)
through the liquid lubricant. At this time, all or part of the
space between the fixed-part plane and the driven-part plane may be
filled with the liquid lubricant. Since the liquid lubricant exists
between the fixed-part plane and the driven-part plane, the
driven-part plane faces the fixed-part plane such that the
driven-part plane is substantially parallel to the fixed-part
plane.
This makes it possible to preferably drive the driven part in the
direction substantially parallel to the fixed-part plane. Moreover,
since the liquid lubricant allows the distance between the
driven-part plane and the fixed-part plane to be kept almost
constant, substantially constant, or always constant, it is
possible to preferably prevent such a disadvantage that the
position of the driven part is changed in the substantially
orthogonal direction to the fixed-part plane.
In addition, the liquid lubricant allows the driven part to be
supported in a form of so-called surface shape with respect to the
fixed part. Thus, even if the driven part is thinned, the liquid
lubricant allows the driven part to maintain the planarity,
strength, and the like. This makes it possible to relatively reduce
the driven part in size or thickness. The construction that the
driven part is relatively reduced in size or thickness is a great
advantage in a micro domain such as MEMS.
Moreover, since the driven part can be relatively reduced in size
or thickness, it is possible to preferably drive the driven part
even if a driving force necessary to drive the driven part is
relatively reduced; namely, it is possible to relatively reduce the
driving force to drive the driven part. This allows achievement of
the simplified and miniaturized actuator which supplies the driving
force necessary to drive the driven part. The simplified and
miniaturized structure as described above is a great advantage in
the micro device such as MEMS.
As described above, according to the embodiment of the driving
apparatus in the embodiment, it is possible to preferably drive the
driven part.
In one aspect of the embodiment of the driving apparatus of the
present invention, there is a balance among (i) a surface tension
that driven-part plane receives in a direction of crossing the
driven-part plane from the lubricant, (ii) a repulsion that the
driven-part plane receives in a direction of crossing the
driven-part plane from the lubricant, and (iii) a force that the
driven-part plane receives in the direction of crossing the
driven-part plane from an element other than the lubricant.
According to this aspect, regardless of the direction or aspect in
which the driving apparatus is placed, the liquid lubricant allows
the distance between the driven-part plane and the fixed-part plane
to be kept almost constant, substantially constant, or always
constant. Thus, it is possible to preferably prevent such a
disadvantage that the position of the driven part is changed in the
substantially orthogonal direction to the fixed-part plane.
In another aspect of the embodiment of the driving apparatus of the
present invention, the driven-part plane forms a depression with
respect to a surface of the driven part in a surrounding of the
driven-part plane.
According to this aspect, it is possible to relatively reduce the
driven part in size or thickness. Even if the driving part is
reduced in size or thickness, the liquid lubricant allows the
driven part to maintain the planarity, strength, and the like.
Moreover, if the liquid lubricant is provided for the portion which
forms the depression (i.e. the driven-part plane), it is possible
to relatively increase the degree of freedom of the design for a
portion other than the portion which forms the depression. More
specifically, the size, shape, or the like of the portion other
than the portion which forms the depression can be determined
without consideration of the liquid lubricant.
Incidentally, the "depression" in the present invention indicates a
portion which is relatively thin compared to another portion (more
specifically, which is relatively thin in the substantially
orthogonal direction to the fixed-part plane). In other words, this
aspect indicates that the thickness of the driven-part plane
provided with the liquid lubricant is less than the thickness of
the portion other than the driven-part plane. In the meanwhile, the
depression has an arbitrary shape.
In another aspect of the embodiment of the driving apparatus of the
present invention, the driven-part plane forms a projection with
respect to a surface of the driven part in a surrounding of the
driven-part plane.
According to this aspect, if the liquid lubricant is provided for
the portion which forms the projection (i.e. the driven-part
plane), it is possible to relatively increase the degree of freedom
of the design for a portion other than the portion which forms the
projection. More specifically, the size, shape, or the like of the
portion other than the portion which forms the projection can be
determined without consideration of the liquid lubricant.
Incidentally, the "projection" in the present invention indicates a
portion which is relatively thick compared to another portion (more
specifically, which is relatively thick in the substantially
orthogonal direction to the fixed-part plane). In other words, this
aspect indicates that the thickness of the driven-part plane
provided with the liquid lubricant is greater than the thickness of
the portion other than the driven-part plane. In the meanwhile, the
projection has an arbitrary shape.
In another aspect of the embodiment of the driving apparatus of the
present invention, the fixed-part plane forms a depression with
respect to a surface of the fixed part in a surrounding of the
fixed-part plane.
According to this aspect, the fixed part can be relatively reduced
in size or thickness. Even if the fixed part is relatively reduced
in size or thickness, the liquid lubricant allows the fixed portion
to maintain the planarity, strength, and the like, so no
disadvantage occurs.
Moreover, if the liquid lubricant is provided for the portion which
forms the depression (i.e. the fixed-part plane), it is possible to
relatively increase the degree of freedom of the design for a
portion other than the portion which forms the depression. More
specifically, the size, shape, or the like of the portion other
than the portion which forms the depression can be determined
without consideration of the liquid lubricant.
In another aspect of the embodiment of the driving apparatus of the
present invention, the fixed-part plane forms a projection with
respect to a surface of the fixed part in a surrounding of the
fixed-part plane.
According to this aspect, if the liquid lubricant is provided for
the portion which forms the projection (i.e. the fixed-part plane),
it is possible to relatively increase the degree of freedom of the
design for a portion other than the portion which forms the
projection. More specifically, the size, shape, or the like of the
portion other than the portion which forms the projection can be
determined without consideration of the liquid lubricant.
In another aspect of the embodiment of the driving apparatus of the
present invention, the driven-part plane forms a depression with
respect to a surface of the driven part in a surrounding of the
driven-part plane, and the fixed-part plane forms a projection,
which corresponds to the depression, with respect to a surface of
the fixed part in a surrounding of the fixed-part plane.
According to this aspect, the driven-part plane which forms the
depression is fitted in the fixed-part plane which makes the
projection. Thus, the space between the driven-part plane and the
fixed-part plane can be preferably filled with the liquid
lubricant, and it is possible to preferably prevent an
unintentional outflow of the liquid lubricant.
In another aspect of the embodiment of the driving apparatus of the
present invention, the driven-part plane forms a projection with
respect to a surface of the driving part in a surrounding of the
fixed-part plane, and the fixed-part plane forms a depression,
which corresponds to the projection, with respect to a surface of
the fixed part in a surrounding of the fixed-part plane.
According to this aspect, the driven-part plane which forms the
projection is fitted in the fixed-part plane which forms the
depression. Thus, the space between the driven-part plane and the
fixed-part plane can be preferably filled with the liquid
lubricant, and it is possible to preferably prevent an
unintentional outflow of the liquid lubricant.
In another aspect of the embodiment of the driving apparatus of the
present invention it is further provided with a driving mechanism
for driving the fixed part in a substantially orthogonal direction
to the fixed-part plane.
According to this aspect, it is possible to drive the driven-part
plane in a planar manner in the direction substantially parallel to
the fixed-part plane, and to drive the fixed part in the
substantially orthogonal direction to the fixed-part plane. As a
result, it is possible to drive the driven-part plane, so-called
three-dimensionally.
While the driven-part plane is driven three-dimensionally, the
liquid lubricant makes it possible to receive the aforementioned
various advantageous effects.
In another aspect of the embodiment of the driving apparatus of the
present invention, each of the fixed part and the driven part is
formed of a same substrate.
According to this aspect, since each of the fixed part and the
driven part can be formed of the same substrate, the driving
apparatus can be manufactured at low cost.
(Embodiment of Recording/Reproducing Apparatus)
An embodiment of the recording/reproducing apparatus of the present
invention is a recording/reproducing apparatus provided with: a
fixed part having a fixed-part plane; and a driven part having a
driven-part plane, which faces the fixed-part plane, and driven in
a direction substantially parallel to the fixed-part plane, a
liquid lubricant being between the fixed-portion plane and the
driven-part plane, the driven-part plane facing the fixed-part
plane such that the driven-part plane is substantially parallel to
the fixed-part plane, the driven part being equipped with a
recording medium, the fixed part being equipped with one or a
plurality of recording/reproducing devices.
According to the embodiment of the recording/reproducing apparatus
of the present invention, the recording medium equipped for the
driven part is displaced in the direction substantially parallel to
the fixed-part plane. The recording/reproducing device equipped for
the fixed part allows information recording/reproduction with
respect to the recording medium. Therefore, it is possible to
record and reproduce the information with respect to the recording
medium while receiving various benefits of the aforementioned
embodiment of the driving apparatus of the present invention.
Incidentally, the one or the plurality of recording/reproducing
devices may be equipped for the fixed part directly or indirectly
through some member(s) or the like between the
recording/reproducing device(s) and the fixed portion.
Incidentally, in response to various aspects of the aforementioned
embodiment of the driving apparatus of the present invention, the
embodiment of the recording/reproducing apparatus of the present
invention can also adopts various aspects.
The operation and other advantages of the present invention will
become more apparent from the examples explained below.
As explained above, according to the embodiment of the driving
apparatus of the present invention, it is provided with the fixed
part having the fixed-part plane and the driven part having the
driven-part plane, the liquid lubricant being between the
fixed-part plane and the driven-part plane. Therefore, it is
possible to preferably drive the driven part.
EXAMPLES
Hereinafter, examples of the present invention will be explained on
the basis of the drawings.
(1) First Example
Firstly, with reference to FIG. 1 and FIG. 2, the first example of
the driving apparatus of the present invention will be explained.
FIG. 1 is a cross sectional view conceptually showing the structure
of the driving apparatus in the first example. FIG. 2 is a cross
sectional view conceptually showing an aspect when a driven part
provided for the driving apparatus in the first example is
displaced.
As shown in FIG. 1, a driving apparatus 1 in the first example is
provided with a case 11 in a box shape having a fixed-part plane 12
inside. The case 11 has, for example, a size on the order of
millimeters, micrometers, or nanometers; namely, the driving
apparatus 1 in the first example corresponds to a micro device such
as MEMS.
The case 11 is provided with a driven part 13 having a driven-part
plane 14 which faces the fixed-part plane 12, in a position facing
the fixed-part plane 12 from among the inside thereof.
The driven part 13 is connected to a reference part 16 joined to
the case 11, through an actuator 15. The actuator 15 displaces
(i.e. drives) the driven part 13 in directions substantially
parallel to the fixed-part plane 12 (specifically, an x-direction
and a y-direction in FIG. 1). At this time, the reference part 16
indicates a reference of position when the driven part 13 is
displaced. The actuator 15 may use various driving methods such as
electrostatic drive, electromagnetic drive, and mechanical drive,
to displace the driven part 13. Incidentally, for example, a driven
object 200 such as a recording medium described later is mounted on
the stage of the driven part 13.
In the first example, in particular, the space between the
fixed-part plane 12 and the driven-part plane 14 is filled with a
liquid lubricant 30 such that the fixed-part plane 12 is
substantially parallel to the driven-part plane 14. The liquid
lubricant 30 preferably has lubricity and a relatively high surface
tension. However, even without such properties, any liquid or gel
that has lubricity and that has a relatively low surface tension
may be used as the lubricant 30, or any liquid or gel that does not
have lubricity and that has a relatively high surface tension may
be used as the lubricant 30. Alternatively, various types of liquid
or gel that have other properties may be used as the lubricant 30.
In the first example, as such a liquid lubricant 30, for example,
Fomblin is used. Of course, it is obvious that a liquid or gel
other than Fomblin may be used as the lubricant 30.
As described above, since the space between the fixed-part plane 12
and the driven-part plane 14 is filled with the liquid lubricant
30, the driven part 13 can be preferably displaced in the direction
substantially parallel to the fixed-part plane 12 while the
fixed-part plane 12 and the driven-part plane 14 are kept
substantially parallel.
Specifically, as shown in FIG. 2, while the fixed-part plane 12 and
the driven-part plane 14 are kept substantially parallel, the
driven part 13 can be displaced to the left in FIG. 2 (i.e. in the
x-direction). Of course, it is obvious that while the fixed-part
plane 12 and the driven-part plane 14 are kept substantially
parallel, the driven part 13 can be displaced to the right in FIG.
2 (i.e. in the x-direction), to the front side (i.e. in the
y-direction), and to the rear side (i.e. in the y-direction).
Moreover, the lubricant 30 allows the distance between the
fixed-part plane 12 and the driven-part plane 14 to be kept almost
constant, substantially constant, or always constant without making
the driven part 13 what is called float in the air. Thus, it is
possible to preferably prevent such a disadvantage that the
position of the driven part 13 is changed without intentions in the
substantially orthogonal direction to the fixed-part plane 12 and
the driven-part plane 14 (i.e. a vertical direction in FIG. 1 and
hereinafter referred to as a "z-direction" as occasion demands).
Moreover, the meniscus force of the lubricant 30 can preferably
prevent such a disadvantage that the driven 13 floats off the case
11 (i.e. a gap other than the lubricant 30 is generated between the
driven-part plane 14 and the fixed-part plane 12).
Incidentally, in the first example, the following equation holds
true: Fa(z)+Fr(z)+Ksz+mg cos .theta.+ma cos .theta.=0, wherein
Fa(z) is a z-direction component of an attraction applied to the
driven part 13 by the surface tension of the lubricant 30, Fr(z) is
a z-direction component of a repulsion applied to the driven part
13 by the lubricant 30, Ksz is a z-direction component of a force
applied to the driven part 13 by the actuator 15 if the actuator 15
is regarded as a cross spring, mg cos .theta. is a z-direction
component of the gravity applied to the driven part 13, and ma cos
.theta. is a z-direction component of the inertial force applied to
the driven part 13 by the driven part 13 accelerating. This
indicates that the position in the z-direction of the driven part
13 is stabilized independently of the direction of the driving
apparatus 1 and whether or not the driving apparatus 1 remains
stationary. More specifically, it indicates that the position in
the z-direction of the driven part 13 is stabilized, whether the
driving apparatus 1 is placed upside down, diagonally, or not.
Moreover, the aforementioned equation indicates that the position
in the z-direction of the driven part 13 is stabilized even if
there is large impact applied to the driving apparatus 1 (F=ma). In
other words, the driving apparatus 1 in the first example has an
advantage of high impact resistance.
In addition, the liquid lubricant 30 allows the driven part 13 to
be supported in a form of surface with respect to the case 11 (more
specifically, the fixed-part plane 12). Thus, even if the driven
part 13 is thinned, the lubricant 30 allows the driven part 13 to
maintain the planarity, strength, to and the like. This makes it
possible to relatively reduce the driven part 13 in size or
thickness. The construction that the driven part 13 is relatively
reduced in size or thickness is a great advantage in the micro
domain such as MEMS, which needs to be provided with many
constituents in a limited space.
Moreover, since the driven part 13 can be relatively reduced in
size or thickness, the mass of the driven part 13 is inevitably
reduced. This makes it possible to preferably drive the driven part
13 even if a driving force necessary to drive the driven part 13 is
relatively reduced. In addition, since the fixed-part plane 12 and
the driven-part plane 14 are neither directly a real-contacted nor
connected by a structure such as a spring, even if the driving
force necessary to drive the driven part 13 is relatively reduced,
it is possible to preferably drive the driven part 13; namely, it
is possible to relatively reduce the driving force necessary to
drive the driven part 13. This allows achievement of the simplified
and miniaturized actuator 15 which supplies the driving force
necessary to drive the driven part 13. The simplified and
miniaturized structure as described above is a great advantage in
the micro device such as MEMS.
Moreover, since the mass of the driven part 13 can be reduced, the
forces (i.e. the aforementioned ma and mg) applied to the driven
part 13 by external causes such as gravity and acceleration are
reduced. Thus, it is possible to properly eliminate the adverse
effect by external causes when the driven part 13 is driven. This
makes it possible to receive an advantage of increasing the driving
accuracy of the driven part 13.
Incidentally, the driven part 13 (in particular, the portion
thereof in which the driven object 200 is mounted) maintains the
planarity and the strength by virtue of the lubricant 30, so the
driven part 13 may be thinned to the extent that the plane cannot
be maintained if not being supported by the fixed-part plane 12
through the lubricant 30. For example, the driven part 13 may be
thinned to 10 micrometers or less.
Moreover, in FIG. 1 and FIG. 2, the space between the fixed-part
plane 12 and the driven-part plane 14 is filled with the lubricant
30, however, at least one portion of the space between the
fixed-part plane 12 and the driven-part plane 14 may be filled with
the lubricant 30.
Moreover, the fixed-part plane 12 and the driven-part plane 14 are
not necessarily pure planes, and there may be unevenness or the
like. It is only necessary that the fixed-part plane 12 and the
driven-part plane 14 can be regarded as the planes as a whole.
Moreover, in order to prevent a disadvantage of outflow of the
lubricant 30 without intentions (more specifically, an outflow of
the lubricant 30 into a space other than the space that is
originally to be filled with the lubricant 30), a closed space is
preferably filled with the lubricant 30. In order to realize such
construction, for example, as explained in the following second to
eighth examples, the driven-part plane 14 and the fixed-part plane
12 are formed to have a projection or depression in shape, by which
the closed space formed by the projection and the depression may be
filled with the lubricant 30. Alternatively, the lubricant 30 is
encapsulated in a saclike container or the like and the container
or the like is attached on the driven-part plane 14 and the
fixed-part plane 12, by which the closed space formed by the
container or the like may be filled with the lubricant 30.
Alternatively, side walls or the like are provided to be filled
with the lubricant 30 between the driven-part plane 14 and the
fixed-part plane 12, by which the closed space formed by the
driven-part plane 14, the fixed-part plane 12, and the side walls
or the like (moreover, the aforementioned projection and
depression) may be filled with the lubricant 30.
(2) Second Example
Next, with reference to FIG. 3, the second example of the driving
apparatus of the present invention will be explained. FIG. 3 is a
cross sectional view conceptually showing the structure of the
driving apparatus in the second example. Incidentally, the same
constituents as those of the driving apparatus 1 in the first
example carry the same numerical references, and the detailed
explanation thereof will be omitted.
As shown in FIG. 3, a driving apparatus 1a in the second example is
provided with the case 11 having the fixed-part plane 12, as in the
driving apparatus 1 in the first example.
In the driving apparatus 1a in the second example, in particular, a
driven-part plane 14a forms a depression with respect to a
surrounding portion of the driven-part plane 14a.
This makes it possible to receive the same various advantageous
effects as those received by the driving apparatus 1 in the first
example, and also makes it possible to further thin the driven part
13a. Along with that, the driving force necessary to drive the
driven part 13a can be relatively reduced.
Moreover, since the lubricant 30 is in contact with the driven-part
plane 14a which forms the depression, it is possible to relatively
increase the degree of freedom of the design for a portion other
than the driven-part plane 14a (i.e. a portion without contact with
the lubricant 30). More specifically, the sizes shape, or the like
of the portion other than the driven-part plane 14a can be
determined without consideration of the lubricant 30.
With reference to FIG. 4, the surrounding portion of the
driven-part plane 14a will be explained, more specifically. FIG. 4
is a top view conceptually showing the structure when the driving
apparatus in the second example is observed in a z-direction.
As shown in FIG. 4, the "surrounding portion of the driven-part
plane 14a" denotes a partial area of the driven part 13a which
surrounds the driven-part plane 14a, and more preferably a partial
area of the driven part 13a which surrounds the driven-part plane
14a and which is adjacent to the driven-part plane 14a. More
specifically, the "surrounding portion of the driven-part plane
14a" denotes one portion of the area between the driven-part plane
14 and the actuator 15. In this case, the partial area of the
driven part 13a which surrounds the driven-part plane 14a, which is
the "surrounding portion of the driven-part plane 14a, may have an
arbitrary size.
Incidentally, this is the same for a "driven-part plane 14b", a
"driven-part plane 14d", and a "driven-part plane 14e" in the
following explanation.
Moreover, in the following explanation, there is a description of a
"surrounding portion of the fixed-part plane 12 (specifically, a
fixed-part plane 12b, a fixed-part plane 12c, a fixed-part plane
12e, and a fixed-part plane 12f)". The "surrounding portion of the
fixed-part plane 12", as in the "surrounding portion of the
driven-part plane 14a", denotes a partial area of the case 11 which
surrounds the fixed-part plane 12, and more preferably a partial
area of the case 11 which surrounds the fixed-part plane 12 and
which is adjacent to the fixed-part plane 12. In this case, the
partial area of the case 11 which surrounds the fixed-part plane
12, which is the "surrounding portion of the fixed-part plane 12,
may have an arbitrary size.
(3) Third Example
Next, with reference to FIG. 5, the third example of the driving
apparatus of the present invention will be explained. FIG. 5 is a
cross sectional view conceptually showing the structure of the
driving apparatus in the third example. Incidentally, the same
constituents as those of the driving apparatus 1 in the first
example carry the same numerical references, and the detailed
explanation thereof will be omitted.
As shown in FIG. 5, in a driving apparatus 1b in the third example,
as in the driving apparatus 1a in the second example, a driven-part
plane 14b forms a depression with respect to a surrounding portion
of the driven-part plane 14b. In the driving apparatus 1b in the
third example, moreover, a fixed-part plane 12b forms a projection
with respect to the surrounding portion of the fixed-part plane
12b. The depression and projection are formed so that the
projection formed by the fixed-part plane 12b is fitted in or
engaged with the depression formed by the driven-part plane
14b.
This makes it possible to receive the various advantageous effects
received by each of the driving apparatus 1 in the first example
and the driving apparatus 1a in the second example.
In addition, since the projection formed by the fixed-part plane
12b is fitted in the depression formed by the driven-part plane
14b, the space between the driven-part plane 14b and the fixed-part
plane 12b can be preferably filled with the lubricant 30. As a
result, it is possible to preferably prevent an unintentional
outflow of the lubricant 30 (specifically, an outflow into the
portion other than the driven-part plane 14b and the fixed-part
plane 12b).
(4) Fourth Example
Next, with reference to FIG. 6, the fourth example of the driving
apparatus of the present invention will be explained. FIG. 6 is a
cross sectional view conceptually showing the structure of the
driving apparatus in the fourth example. Incidentally, the same
constituents as those of the driving apparatus 1 in the first
example carry the same numerical references, and the detailed
explanation thereof will be omitted.
As shown in FIG. 6, a driving apparatus 1c in the fourth example,
as in the driving apparatus 1 in the first example, is provided
with the driven part 13 having the driven-part plane 14.
In the driving apparatus 1c in the fourth example, in particular,
as in the driving apparatus 1b in the third example, a fixed-part
plane 12c forms a projection with respect to the surrounding
portion of the fixed-part plane 12c.
This makes it possible to receive the same benefits as those
received by the driving apparatus 1 in the first example.
Moreover, since the lubricant 30 is in contact with the fixed-part
plane 12c which forms the projection, it is possible to relatively
increase the degree of freedom of the design for a portion other
than the fixed-part plane 12c (i.e. a portion without contact with
the lubricant 30). More specifically, the size, shape, or the like
of the portion other than the fixed-part plane 12c can be
determined without consideration of the lubricant 30.
(5) Fifth Example
Next, with reference to FIG. 7, the fifth example of the driving
apparatus of the present invention will be explained. FIG. 7 is a
cross sectional view conceptually showing the structure of the
driving apparatus in the fifth example. Incidentally, the same
constituents as those of the driving apparatus 1 in the first
example carry the same numerical references, and the detailed
explanation thereof will be omitted.
As shown in FIG. 7, a driving apparatus 1d in the fifth example, as
in the driving apparatus 1 in the first example, is provided with
the case 11 having the fixed-part plane 12.
In the driving apparatus 1d in the fifth example, in particular, a
driven-part plane 14d forms a projection with respect to a
surrounding portion of the driven-part plane 14d. In other words,
the driven-part plane 14d is formed so as to form the projection on
the bottom side of the driven part 13.
This makes it possible to receive the same various advantageous
effects as those received by the driving apparatus 1 in the first
example.
Moreover, since the lubricant 30 is in contact with the driven-part
plane 14d which forms the projection, it is possible to relatively
increase the degree of freedom of the design for a portion other
than the driven-part plane 14d (i.e. a portion without contact with
the lubricant 30). More specifically, the size, shape, or the like
of the portion other than the driven-part plane 14d can be
determined without consideration of the lubricant 30.
(6) Sixth Example
Next, with reference to FIG. 8, the sixth example of the driving
apparatus of the present invention will be explained. FIG. 8 is a
cross sectional view conceptually showing the structure of the
driving apparatus in the sixth example. Incidentally, the same
constituents as those of the driving apparatus 1 in the first
example carry the same numerical references, and the detailed
explanation thereof will be omitted.
As shown in FIG. 8, in a driving apparatus 1e in the sixth example,
as in the driving apparatus 1d in the fifth example, a driven-part
plane 14e forms a projection with respect to a surrounding portion
of the driven-part plane 14e. In the driving apparatus 1e in the
sixth example, moreover, a fixed-part plane 12e forms a projection
with respect to the surrounding portion of the fixed-part plane
12e. The depression and projection are formed so that the
projection formed by the driven-part plane 14e is fitted in or
engaged with the depression formed by the fixed-part plane 12e.
This makes it possible to receive the various advantageous effects
received by each of the driving apparatus 1 in the first example
and the driving apparatus 1d in the fifth example.
In addition, since the projection formed by the driven-part plane
14e is fitted in the depression formed by the fixed-part plane 12e,
the space between the driven-part plane 14e and the fixed-part
plane 12e can be preferably filled with the lubricant 30. As a
result, it is possible to preferably prevent an unintentional
outflow of the lubricant 30 (specifically, an outflow into the
portion other than the driven-part plane 14e and the fixed-part
plane 12e).
(7) Seventh Example
Next, with reference to FIG. 9, the seventh example of the driving
apparatus of the present invention will be explained. FIG. 9 is a
cross sectional view conceptually showing the structure of the
driving apparatus in the seventh example. Incidentally, the same
constituents as those of the driving apparatus 1 in the first
example carry the same numerical references, and the derailed
explanation thereof will be omitted.
As shown in FIG. 9, a driving apparatus 1f in the seventh example,
as in the driving apparatus 1 in the first example, is provided
with a driven part 13f having a driven-part plane 14f.
In the driving apparatus if in the seventh example, in particular,
as in the driving apparatus 1e in the sixth example, a fixed-part
plane 12f forms a depression with respect to the surrounding
portion of the fixed-part plane 12f.
This makes it possible to receive the same benefits as those
received by the driving apparatus 1 in the first example.
Moreover, since the lubricant 30 is in contact with the fixed-part
plane 12f which forms the depression, it is possible to relatively
increase the degree of freedom of the design for a portion other
than the fixed-part plane 12f (i.e. a portion without contact with
the lubricant 30). More specifically, the size, shape, or the like
of the portion other than the fixed-part plane 12f can be
determined without consideration of the lubricant 30.
(8) Eighth Example
Next, with reference to FIG. 10, the eighth example of the driving
apparatus of the present invention will be explained. FIG. 10 is a
cross sectional view conceptually showing the structure of the
driving apparatus in the eighth example. Incidentally, the same
constituents as those of the driving apparatus 1 in the first
example carry the same numerical references, and the detailed
explanation thereof will be omitted.
As shown in FIG. 10, a driving apparatus 1g in the eighth example
is provided with a case 11g having a plurality of fixed-part planes
12g-1 and 12g-2 whose heights in the z-direction are different from
each other. The driving apparatus 1g in the eighth example is also
provided with a driven part 13g having a plurality of driven-part
planes 14g-1 and 14g-2 whose heights in the z-direction are
different from each other.
As described above, even if the fixed-part planes 12g and the
driven-part planes 14g have portions of different heights in the
z-direction, it is possible to preferably receive various
advantageous effects received by the aforementioned driving
apparatus 1 in the first example.
Of course, the fixed-part planes 12g and the driven-part planes 14g
are not limited to having two portions of different heights in the
z-direction; the fixed-part planes 12g and the driven-part planes
14g may have a plurality of portions whose heights in the
z-direction are different from each other.
(9) Ninth Example
Next, with reference to FIG. 11, the ninth example of the driving
apparatus of the present invention will be explained. FIG. 11 are a
cross sectional view and a top view conceptually showing the
structure of the driving apparatus in the ninth example.
Incidentally, the same constituents as those of the driving
apparatus 1 in the first example carry the same numerical
references, and the detailed explanation thereof will be
omitted.
As shown in FIG. 11(a) and FIG. 11(b), a driving apparatus 1h in
the ninth example adopts a rotary drive method in which a
disc-shaped driven part 13h rotates in a direction denoted by
arrows in FIG. 11(a) and FIG. 11(b). Incidentally, FIG. 11(b) is a
top view showing the driving apparatus 1h observed from the upper
side in FIG. 11(a). Such a driving apparatus 1h is used in, for
example, an optical disc drive, a hard disk drive, or the like.
The driving apparatus 1h in the ninth example, as in the driving
apparatus 1 which adopts the aforementioned planar drive method, is
provided with a case 11h having a fixed-part plane 12h; the
disc-shaped driven device 13h having a disc-shaped driven-part
plane 14h. The space between the fixed-part plane 12h and the
driven-part plane 14h is filled with the liquid lubricant 30 so as
to make the fixed-part plane 12h and the driven-part plane 14h
substantially parallel.
By virtue of such construction, even in the driving apparatus 1h
which adopts the rotary drive method, it is possible to preferably
receive various advantageous effects received by the driving
apparatus 1 in the first example which adopts the aforementioned
planar drive method.
Incidentally, even the driving apparatus 1 in the ninth example can
obviously receive the various advantageous effects received by each
of the driving apparatuses 1a to 1g by adopting the aforementioned
structures of the driving apparatus 1a in the second example to the
driving apparatus 1g in the eight example.
(10) Recording/Reproducing Apparatus
Next, with reference to FIG. 12 and FIG. 13, an explanation will be
given on a recording/reproducing apparatus in an example using the
driving apparatuses in the aforementioned examples. FIG. 12 is a
cross sectional view conceptually showing a first structure of the
recording/reproducing apparatus in an example. FIG. 13 is a cross
sectional view conceptually showing a second structure of the
recording/reproducing apparatus in the example.
As shown in FIG. 12, a recording/reproducing apparatus 100 in the
example is provided with the aforementioned driving apparatus 1 in
the first example. The recording/reproducing apparatus 100 is
further provided with a probe head 41 having a plurality of probes
42, which are connected to the reference part 16.
Each of the plurality of probes 42 constitutes one specific example
of the "recording/reproducing device" of the present invention.
Each of the plurality of probes 42 has a pointed tip, and data is
recorded and reproduced with respect to a recording medium 201 by
applying a voltage from the tip to the recording medium 201.
For example, in case of the recording/reproducing apparatus 100
using the SNDM (Scanning Nonlinear Dielectric Microscopy)
principle, data denoted by the polarization direction of a
ferroelectric substance is recorded by applying electric fields
beyond the coercive electric field of the ferroelectric substance
from the tips of the probes 42 to the recording medium 201 which is
formed of the ferroelectric substance. On the other hand, in the
reproduction, the data recorded as the polarization direction of
the ferroelectric substance is read and reproduced by applying
alternate electric fields to the ferroelectric substrate and
detecting a difference in a capacitance Cs or a difference in a
change in the capacitance Cs in a certain micro domain of the
ferroelectric substance at that time.
Of course, the recording/reproducing apparatus is not limited to
the apparatus using the SNDM principle but may be the apparatus
using various methods.
At this time, in order to record data into a recording area at a
desired position of the recording medium 201 or in order to
reproduce the data recorded in the desired recording area of the
recording medium, the driven part 13 with the recording medium 201
mounted thereon is displaced by the operation of the actuator
15.
Therefore, according to the recording/reproducing apparatus 100 in
the example, it is possible to record and reproduce the data with
respect to the recording medium 201 while receiving the various
advantageous effects received by the aforementioned driving
apparatus 1 in the first example.
Incidentally, even recording/reproducing apparatus 100 in the
example can obviously receive the various advantageous effects
received by each of the driving apparatuses 1a to 1g by adopting
the aforementioned structures of the driving apparatus 1a in the
second example to the driving apparatus 1g in the eighth
example.
Moreover, in the recording/reproducing apparatus 100 in the
example, the probe head 41 is disposed in the case 11 through the
reference part 16. As described above, the probe head 41 may be
indirectly disposed in the case 11 through a predetermined member.
The probe head 41, however, may be directly disposed in the case
11. In short, there is no limit to the construction that the probe
41 is disposed in the case 11 as long as the probe head 41 is fixed
to the case 11.
Incidentally, the recording/reproducing apparatus 100 shown in FIG.
12 displaces the recording medium 201 on the plane (i.e. in each of
the x-direction and the y-direction). The recording medium 201,
however, may be displaced in a so-called three-dimensional
direction (i.e. in each of the x-direction, the y-direction, and
the z-direction).
Specifically, as shown in FIG. 13, the recording/reproducing
apparatus 100 may be provided with an actuator 50 for displacing
the driven part 13 in the z-direction with the lubricant 30. In
this case, the actuator 50 is fixed to the inner wall of the case
11, and the surface of the actuator 50 facing the driven-part plane
14 corresponds to the fixed-part plane 12.
By virtue of such construction, it is possible to displace the
driven part 13 in the z-direction by the operation of the actuator
50 while receiving various advantage effects received by the
driving apparatus 1 in the first example or the like. That is,
while the driven part 13 is displaced in the z-direction by the
operation of the actuator 50, it is possible to prevent such an
unintentional change in the position of the driven part 13 in the
z-direction that is caused by an element other than the operation
of the actuator 50 (e.g. the operation of the actuator 13).
Incidentally, here, an explanation was given on such an example
that the driving apparatus 1 in the first example to the driving
apparatus 1h in the ninth example are applied to the
recording/reproducing apparatus 100. However, the driving apparatus
1 in the first example to the driving apparatus 1h in the ninth
example are not limited to being applied to the
recording/reproducing apparatus; the apparatuses may be applied to
a stage provided for an electron beam drawing apparatus, SEM
(Scanning Electric Microscopy), SPM (Scanning Probe Microscopy),
and the like. The driving apparatus 1 is preferably applied to the
micro device.
(11) Manufacturing Process
Next, with reference to FIG. 14, a manufacturing process of the
aforementioned driving apparatus 1 in the first example will be
explained. FIG. 14 are cross sectional views conceptually showing
the manufacturing process of the driving apparatus 1 in the first
example.
As shown in FIG. 14(a), for the manufacturing of the driving
apparatus 1 in the first example, a SOI (Silicon On Insulation)
substrate is used in which a silicon dioxide layer 302 is
sandwiched between a silicon layer 301 and a silicon layer 302.
As shown in FIG. 14(b), the actuator 15 is formed by performing a
patterning process, an etching process, a deposition process, or
the like. This results in the structure that the driven part 13 is
connected to the reference part 16 joined to the case 11, through
the actuator 15.
Then, as shown in FIG. 14(c), sacrifice layer etching is performed
on the silicon dioxide layer 302, which is under the driven part 13
and the actuator 15, by which the space to be filled with the
lubricant 30 is formed. The upper surface of the space is in
contact with the driven-part plane 14 of the driven part 13, and
the lower surface of the space is in contact with the fixed-part
plane 12 of the case 11.
Then, as shown in FIG. 14(d), the space formed by the sacrifice
layer etching is filled with the lubricant 30. By this, the driving
apparatus 1 in the first example is manufactured.
By manufacturing the driving apparatus 1 in the first example from
the single SOI substrate in this manner, it is no longer necessary
to align the fixed-part plane 12 of the actuator 15 or the like (or
the case 11). Moreover, it can save the trouble of incorporating
the actuator 15 or the like. Therefore, it is possible to
manufacture the driving apparatus 1 in the first example,
relatively easily and simply.
Incidentally, the manufacturing process explained with reference to
FIG. 14 is one specific example of the manufacturing process of the
driving apparatus 1 in the first example. The driving apparatus 1
in the first example is obviously allowed to be manufactured in a
manufacturing process other than the manufacturing process in the
aspect shown in FIG. 14.
Moreover, it is obvious that the driving apparatus 1a in the second
example to the driving apparatus 1h in the ninth example, and the
recording/reproducing apparatuses 100 and 101 may be manufactured
in the aspect shown in FIG. 14 or in a manufacturing process other
than the manufacturing process in the aspect shown in FIG. 14, as
in the driving apparatus 1 in the first example.
The present invention is not limited to the aforementioned
examples, but various changes may be made, if desired, without
departing from the essence or spirit of the invention which can be
read from the claims and the entire specification. A driving
apparatus, and a recording/reproducing apparatus, all of which
involve such changes, are also intended to be within the technical
scope of the present invention.
* * * * *